The skin is a natural barrier to the penetration of foreign substances. The stratum corneum is the superficial cornified layer of the skin that provides a barrier to water evaporation and reduces the permeation of undesirable molecules from the external environment. The stratum corneum consists of dead cells called corneocytes, which are embedded in a lipid-rich matrix of fatty-acids, ceramides, and cholesterols. This structure of corneocytes embedded in lipids is thought to provide many of the barrier properties of the skin. Substances deposited on the skin must traverse this structure through a tortuous path to gain access to the underlying viable layers of the skin. Skin inflammation occurs when substances which are irritating to the skin are able to penetrate this barrier and initiate an elaborate cascade of immunological events once they contact the skin cells in the viable epidermis and dermis layers. As the skin barrier is compromised, skin is subject to inflammatory events from percutaneous absorbtion of irritants through the stratum corneum.
Skin barrier function can be compromised by a variety of insults that cause inflammation. Insults to the skin, can include, but are not limited to, environmental irritants, mechanical abrasion, continuous tissue load pressure, exposure to body fluids and waste, and exposure to chemicals. For example, physical and chemical treatments, abrasion, tape stripping, ultrasonics, electrical fields, enzymes, solvents, surfactants, and elevated ambient humidity are known to diminish skin barrier function. Bodily fluids and wastes may contain skin irritants in the form of enzymes such as proteases, ureases, and lipases. Enzymes found in feces cleave the stratum corneum proteins and cause the breakdown of the natural barrier of the skin. Bacterial ureases on the skin convert the urea in urine to ammonia resulting in an alkaline pH on the skin. Prolonged exposure of the skin to these enzymes is thought to be a major cause of skin damage that leads to dermatitis and subsequent skin breakdown. In addition, the care of skin in individuals with ostomies is difficult due to the frequent contact of digestive enzymes with skin surrounding the ostomy site. These enzymes can degrade the skin surface and cause severe skin breakdown and partial thickness wounds.
A number of approaches are known for protecting the skin against the action of skin irritants and subsequent skin breakdown. Examples include protective apparel, skin protectant formulations, and anti-inflammatory compositions. Protective apparel garments may prevent irritants from contacting the skin, or may be used to prevent dissemination of irritants from bodily fluids to the surrounding environment, for example, diapers or adult incontinence garments. However, the use of barrier materials in these garments prevents movement of moisture and air and therefore, proliferates an environment in which skin may be kept in contact with the irritants and increase the damage.
Many of the skin protectant formulations commercially available may not provide adequate protection against skin irritants. Many of these formulations consist of softening creams and hydrating compounds to replenish the moisture content of the skin. However, these formulations do not block the irritants present in urine, feces, or blood such as, for example, the proteolytic enzymes present in feces. Furthermore these compositions often consist of petrolatum, lanolin or greasy compounds that can rub off onto garments and decrease the absorbency of the garment.
Another method of treating skin irritation is the topical use of anti-inflammatory compounds. However, the topical use of anti-inflammatory compounds does not protect the skin from coming in contact with an irritant, therefore, damage to the skin still occurs. The anti-inflammatory substance mitigates the inflammatory response but it does not prevent the skin damage that elicits the inflammatory event in the first place.
What is needed in the art is a skin protectant cream that can be applied directly to the skin to provide a barrier from contact with irritants, block the activity of enzymes found in bodily fluids and feces, and can enhance the barrier properties of the skin. What is also needed in the art is a skin protectant cream that will remain on the skin to continue to provide a barrier, block the activity of enzymes, and replenish the barrier properties of the skin. What is also needed in the art are disposable application articles to apply the skin protectant cream. These and other needs are provided by the present invention.